Also called: Japanese honorifics AI, keigo generation
Keigo is the Japanese honorific system that encodes the relationship between speaker, listener and referent, and AI assistants handle it unreliably because the correct level is determined by social context the model is not given rather than by the sentence being translated.
The error is rarely grammatical; it is a wrong relationship, which reads as rude rather than as a mistake.
A model can inflect sonkeigo, kenjougo and teineigo correctly and still be wrong, because choosing among them requires knowing who outranks whom, how close the parties are, and whether the writer is speaking for themselves or for their company. None of that is in the source sentence.
The consequence is asymmetric risk. English written slightly too formally is mildly odd. Japanese written at the wrong level of keigo damages the relationship the message exists to maintain, and the writer often cannot see the damage in their own second language.
| Determinant | Example | Available to the model by default? |
|---|---|---|
| Relative seniority | Writing to a client's director versus a peer | No |
| In-group or out-group | Referring to your own manager to an outsider | No |
| Prior correspondence register | The level the counterpart used first | Only if the thread is supplied |
| Industry convention | Finance versus startup norms | Partially, and unevenly |
| Grammatical forms themselves | irassharu, itadaku, desu/masu | Yes |
Cite this page
MyWritingTwin. “Keigo and AI.” Last updated 2026-09-15. https://www.mywritingtwin.com/glossary/keigo-and-ai